We present the first infrared ellipsoidal study of a low-mass X-ray binary system, and hence measure the mass of the neutron star. Photometry of Cen X-4 obtained during 1990-91 allows us to determine the quiescent light curve. By fitting this light curve with an ellipsoidal model we revise the ephemeris, obtain solutions in the mass ratio

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Results are presented from a large observational project directed toward the detection of solar-like oscillations in an ensemble of open cluster stars. Seven groups collaborated in 1992 January to observe twelve stars in M67 with 4 m class telescopes for a one week period. High quality time series were collected on 22 telescope nights for a total

In the first two papers of this series, we derived and discussed the abundances of lithium in a sample of 161 galactic carbon stars. Here, we extend this sample to 203 stars and we present the spectra from which these abundances were derived, as well as a tabulation of the equivalent widths of the λ6708 Å feature. A comparison of our measurements

The evolution and spectra from a compact supernova remnant evolving in a high-density circumstellar medium with a density of 107cm-3 are presented. The radiation emitted by the shocked region can self-ionize the cooling shell and a large region of the surrounding medium. The resulting line ratios from the photoionized zones are similar to those

We present high spectral and spatial resolution spectroscopy of the nuclear starburst region of the galaxy NGC 253. Two slit positions, matching the major and minor axes on the galaxy, have been taken. These cover H-alpha and (N II) lines as well as the (S II) doublet. The attained resolution, together with good seeing conditions, have allowed the